With the gradual increasing of panel resolution, the number of output channels of a source driver is increasing rapidly, for example, the number of the output channels(CH) of a single chip integrated source driver increases to 2400 CH, or even 3600 CH from a previous 1800 CH. If a previous production process is to be maintained, that is a line width and a line interval of the source output channel in a Fan-out region of the source driver to be unchanged, it will inevitably lead to an increasing of the Fan-out region and cause a bottom frame of a display panel to be wider, which is inconsistent with the market demand for a narrow frame.
Therefore, in order to meet market demands, designers of the display panel must reduce the line width and line interval of the source output channel, which will inevitably lead to an increasing of a wiring resistance of the source output channel (equivalent to a case that a resistance of a conductive wire of a specified material becomes greater as a cross-sectional area of the conductive wire becomes smaller). In that case, a difference between the resistances of the output channels at the middle and the edge of source driver may be great, for example, the resistance of the middle channel in the Fan-out area is only 200Ω, while the resistance of the edge channel in the Fan-out area may be up to 2000Ω (mainly because the fan-out wiring of the edge channel is longer in length than that of the middle channel).
However, in order to solve a problem of differences among phase delays in the source output signals of the respective channels caused by the great differences in the above resistances, usually, a bias current of the entire source driver is set according to the signal phase delays at the edge channels, such that the bias current may drive the source output signals at the edge channels normally but an over-driving phenomenon exists in the source output signals at the middle channels. That is, although the middle channel does not require the bias current with a large amplitude, but it also has to be driven by a bias current which may exceed the required amplitude in order to guarantee the normal driving of the edge channel, therefore it results in an unnecessary increasing in the power consumption of the source driver, which in turn causes a significant increasing in the power consumption of the display panel.